They search out iniquities; they accomplish a diligent search: both the inward thought of every one of them, and the heart, are deep.
Read Chapter 64
Augustine of Hippo
9. "They have searched out iniquity, they have failed, searching searchings" (ver. 6): that is, deadly and acute designs. Let Him not be betrayed by us, but by His disciple: let Him not be killed by us, but by the judge: let us do all, and let us seem to have done nothing. ...
10. But what befell them? "They failed searching searchings." Whence? Because he saith, "Who shall see them?" that is, that no one saw them. This they were saying, this among themselves they thought, that no one saw them. See what befalleth an evil soul: it departeth from the light of truth, and because itself seeth not God, it thinketh that itself is not seen by God. ...
11. For what followeth? "There shall draw near a man and a deep heart." They said, Who shall see us? They failed in searching searchings, evil counsels. There drew near a man to those same counsels, He suffered Himself to be held as a man. For He would not have been held except He were man, or have been seen except He were man, or have bee...
Search. Or, they have made the most diligent investigation, (Berthier) to no purpose. (Haydock)
Thus David and our Saviour were treated.
Heart. That is, crafty, subtle, deep projects and designs; which nevertheless shall not succeed; for God shall be exalted in bringing them to nought, by his wisdom and power. (Challoner)
Hebrew, "both the inward thought of every one of them, and the heart is deep. "(Protestants) (Haydock)
But, without the points, the Septuagint is accurate. (Berthier)
The Jews, with all their deep machinations to prevent the belief of Christ's resurrection, bringing even sleeping witnesses, only made themselves ridiculous. (St. Augustine) (Haydock)
Achitophel was forced to give way, (2 Kings xvii.; Worthington) though he had been considered as an oracle. (Haydock)